HIRA and Intellectual disability: We consider four key protein complexes: chromatin assembly factor 1 (CAF-1) complex, histone regulator A (HIRA) complex, death domain-associated and alpha-thalassemia/mental retardation, X-linked protein (DAXX/ATRX) complex, and Holliday junction recognition protein (HJURP) complex (Figure 3A, top row).